A variety of medical fabrics for use during surgical procedures are known in the art. A multitude of fabric materials in and of themselves have been developed which exhibit desirable properties for their use, such as fluid penetration resistant materials to reduce the likelihood of transporting microbes between patients and health care professionals. Medical fabrics are typically formed or converted into forms that are useful in a surgical setting, such as contamination-resistant drapes or clothing. Contamination resistance of the fabric material per se has been a primary focal point of interest in the field of medical fabrics.
Heat sealing techniques, such as thermal sealing or ultrasonic welding, are known to be useful in the field of medical fabrics to form seals or barriers upon fusing two portions of material to one another. U.S. Pat. No. 5,444,873 to Levin, for example, describes one such application of heat sealing to join the sleeve portion of a surgical gown to the body of the gown by a welded interface at the sealing juncture. Similarly, U.S. Pat. No. 4,635,628 to Hubbard et al. describes a surgical facemask with a moisture barrier utilizing heat seal bonding techniques.
Multilaminate materials which are fluid impervious and useful during surgical procedures also are known. Multilaminate materials that exhibit fluid barrier properties while at the same time affording transport of water vapor through the material also have been developed. Such multilaminate materials can include a breathable flexible thermoplastic film such as ARNITEL™ available from DSM Engineering Co., Sittard, the Netherlands.
Surgical gowns have been used in the medical community to protect health care professionals from liquids and microorganisms during surgical and other high fluid procedures. Such gowns typically include a single body panel including a front portion, a pair of back portions on the sides of the front portion and extend away from the front portion, and a pair of sleeves which are provided at the juncture of the front and side portion. The front portion covers the front of the health care professional during the procedure. The back portions are secured around and overlap each other to cover the rear of the health care professional and a tying structure. The sleeves cover the arms of the health care professional during the procedure. Because of the proximity of the sleeves and arms of the health care professional to the high fluid procedures, the fluid imperviousness of the sleeves carries a special importance. Likewise, surgical drapes are used to maintain a sterile field in surgery.
Because of the differing properties amongst and between the individual layers from which multi-laminated materials are composed, different layers respond to and are affected by various seam construction techniques in different ways. One method of adjoining two portions of medical fabrics that can be almost universally employed in the field is folding and stitching techniques. While adequate for securing two fabric portions, stitching does not by alone offer fluid impervious properties to the seam with respect to the surrounding environment. Adhesive seals alone or in combination with stitching, such as for example those described in U.S. Pat. No. 4,114,200 to Smith et al., do not necessarily offer consistent penetration-resistant properties to a seam. The barrier of an impervious seam held together by adhesive techniques is dependent upon the thoroughness of applying the adhesive to the surface of the material. General heat sealing techniques typically “weld” all of the layers holistically, or weld only some of the layers in an incomplete manner.
While heat sealing techniques to fuse two overlapping materials are known in the art, these prior attempts utilize materials and heat sealing techniques with properties such that the binding may appear to be fluid impervious, but may not be, as penetration can occur that is not visible or obvious. For example, U.S. Pat. No. 3,486,964 to Brunlid describes sheet material having an overlap seam and method of forming same. Two margins of sheet material are joined by an overlap seam, with one margin overlying the other margin and with its free edge abutting against and sealed to a ridge formed in the sheet material adjacent to the other margin. When the seat material consists of two outer plastic layers (e.g., polyethylene or polypropylene) and an intermediate porous layer such as paper and margins are joined by heat sealing, a continuous plastic surface is formed and the free edge of the intermediate layer is covered with plastic. The reference contains no teaching or suggestion of multi-layered fabrics for medical use, nor does it specifically discuss fluid barrier properties in a medical environment.
Similarly, U.S. Pat. No. 4,695,334 to Mays describes a method of making water impervious materials. A preferred embodiment comprises a three-layer plastic film sandwiched between and fuse bonded to two layers of conjugate fibers having a low melting sheath and a high melting core. The inner layer of the plastic film is relatively high melting while the two outer plies of the film are low melting. The sheaths of the conjugate fibers have been fuse bonded to the plastic film at a temperature below the melt temperature of the cores of the conjugate fibers so that the cores retain their initial fiber-like integrity. The reference is directed to the formation of a unitary laminate material per se from two separate multi-layered sheets, and does not teach or suggest an overlapped seam arrangement formed by such a fusion.
Also, U.S. Pat. No. 5,766,400 to Gallagher, Jr. describes a prefabricated multi-layered flexible product that can be used as a liner for an outer shell or as a stand-alone product. A substrate fabric material is placed in parallel with a synthetic film membrane to form a two ply laminate, and with outer substrate fabric material(s) to form multi-ply laminates. A thermoplastic film is placed in-between the layers to enhance bonding. The laminate(s) and/or separate sheets of above materials are assembled by using a radio frequency welding process and then cut into two or three dimensional forms, which in their bonded state form either a prefabricated component liner or a prefabricated stand alone product. The form may be a glove, sock, shirt, boot/shoe, hat, jacket, pant, etc. The reference does not teach or suggest a sterile barrier-type product suitable for a medical environment.
Thus, difficulty has been encountered in obtaining a product composed of a multi-layer fluid impervious material wherein the seams in the product exhibit the same fluid penetration resistant properties as the material per se but which can also be created using heat sealing techniques. There exists a need for improvements relating to methods for making seams in surgical products made from fluid impervious multi-layered fabrics in which the seam is sealed in a manner which exhibit fluid penetration resistant characteristics similar to the base material.